Conservation of the world water supply is becoming increasingly important. In the United States, it has been reported that Americans use an average of 101 gallons of water per day, while only about 20.5 gallons per day are needed to maintain life, hygiene and food production. Given that landscape needs are estimated to account for between 20% and 50% of the 95,000 gallons of water consumed by the average U.S. household per year, conserving water used for landscaping presents an important opportunity in the global efforts to conserve water.
Water conservation techniques in many areas are known. In the landscape irrigation field, controlling the duration and timing of watering and using more efficient watering devices are useful first steps to reducing water usage. Planning water-efficient landscapes by using plants more acclimated to their surroundings, for example, more drought-resistant plants in arid areas, also aids water conservation. Using automated control systems instead of hand watering or using soaker hoses, for instance, avoids overwatering and losses from evaporation or runoff. Additionally, controlled irrigation systems conserve water by targeting different zones of a landscape and delivering only as much water as necessitated by a particular landscape, based in part by recent climate considerations. While these efforts have been useful, there remains meaningful room for improvement.
A largely untapped water-conservation resource is the use of harvested water. Harvested water may include rainwater recapture, landscape runoff, irrigation runoff, HVAC (heating, ventilating, and air conditioning) condensate and gray (or grey) water. Gray water is waste water produced from mainly domestic uses such as using showers, sinks, washing machines, dishwashers, and washing cars. In most domestic and commercial settings, gray water is not separated from black water (septic waste from toilets) and both are fed into a local sewer system. Because it contains organic waste, bacteria and other harmful components, black water must be disposed of in this manner. However, gray water most often is safe enough for reuse in a variety of applications after minimal or no treatment. Currently, systems exist to reuse harvested water in place of potable (fresh) water in very limited applications, such as for flushing toilets, washing cars, and irrigating landscapes. These uses, especially in irrigation, are often heavily regulated, if permitted at all. However, some areas, especially those constantly plagued by water shortages, are loosening harvested water restrictions, creating a valuable opportunity for harvested water-type irrigation systems.
While existing systems may reclaim harvested water for use in irrigation, they often do not consider that the harvested water produced from a given source may not fulfill or precisely match the irrigation needs of that particular area. Moreover, the systems often are not designed to account for other common sources of waste during irrigation. Thus, a need remains for easy and economical utilization of harvested water systems that allow integrated control of a harvested water irrigation system in a user-friendly fashion to achieve maximum water-saving benefits, especially for residential and commercial irrigation purposes.